// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_H_
#define CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_H_

#include <memory>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "media/audio/audio_output_ipc.h"

namespace media {
class AudioParameters;
}

namespace base {
class SingleThreadTaskRunner;
}

namespace content {
class AudioHelper;

class PepperPlatformAudioOutput
    : public media::AudioOutputIPCDelegate,
      public base::RefCountedThreadSafe<PepperPlatformAudioOutput> {
public:
    // Factory function, returns NULL on failure. StreamCreated() will be called
    // when the stream is created.
    static PepperPlatformAudioOutput* Create(int sample_rate,
        int frames_per_buffer,
        int source_render_frame_id,
        AudioHelper* client);

    // The following three methods are all called on main thread.

    // Starts the playback. Returns false on error or if called before the
    // stream is created or after the stream is closed.
    bool StartPlayback();

    // Stops the playback. Returns false on error or if called before the stream
    // is created or after the stream is closed.
    bool StopPlayback();

    // Sets the volume. Returns false on error or if called before the stream
    // is created or after the stream is closed.
    bool SetVolume(double volume);

    // Closes the stream. Make sure to call this before the object is
    // destructed.
    void ShutDown();

    // media::AudioOutputIPCDelegate implementation.
    void OnError() override;
    void OnDeviceAuthorized(media::OutputDeviceStatus device_status,
        const media::AudioParameters& output_params,
        const std::string& matched_device_id) override;
    void OnStreamCreated(base::SharedMemoryHandle handle,
        base::SyncSocket::Handle socket_handle,
        int length) override;
    void OnIPCClosed() override;

protected:
    ~PepperPlatformAudioOutput() override;

private:
    friend class base::RefCountedThreadSafe<PepperPlatformAudioOutput>;

    PepperPlatformAudioOutput();

    bool Initialize(int sample_rate,
        int frames_per_buffer,
        int source_render_frame_id,
        AudioHelper* client);

    // I/O thread backends to above functions.
    void InitializeOnIOThread(const media::AudioParameters& params);
    void StartPlaybackOnIOThread();
    void StopPlaybackOnIOThread();
    void SetVolumeOnIOThread(double volume);
    void ShutDownOnIOThread();

    // The client to notify when the stream is created. THIS MUST ONLY BE
    // ACCESSED ON THE MAIN THREAD.
    AudioHelper* client_;

    // Used to send/receive IPC. THIS MUST ONLY BE ACCESSED ON THE
    // I/O thread except to send messages and get the message loop.
    std::unique_ptr<media::AudioOutputIPC> ipc_;

    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
    scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;

    DISALLOW_COPY_AND_ASSIGN(PepperPlatformAudioOutput);
};

} // namespace content

#endif // CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_H_
